1. Field of the Invention
The present invention relates to a device for reducing the vibration of a control object, which can be applied to reduce the high-frequency vibration of the control object. A fuel injector of an internal combustion engine is one such control object that has a high-frequency vibration to be reduced.
2. Description of Related Art
In a direct-injection diesel engine, fuel that has been compressed to a high pressure is directly sprayed into the cylinders by fuel injectors. The fuel injectors may be supported, for example, by known structures. That is, the fuel injector may be installed in a fuel injector mounting hole formed in the cylinder head, and pressed and fixed in the cylinder head by a nozzle support. The nozzle support includes a forked part that terminates in two prongs, is placed over the fuel injector, is supported on the head main body at a supporting point on the opposite end, and is fastened with a bolt on the cylinder head. The axial force of the bolt is transferred to the forked part of the nozzle support, and the fuel injector is pressed and fixed on the cylinder.
The fuel injector includes a needle valve and other moving elements. The lifting/retraction of the needle valve against the seat, controls the injection of fuel. The opening and closing of the needle valve in the fuel injector generates an impact force due to collision. Specifically, in a common rail type diesel engine, as the internal elements of the fuel injector are driven by the high-pressure fuel, the impact force generated in the fuel injector is high. As the fuel injector vibrates due to the impact force, the vibration is transmitted via the nozzle support and cylinder head connected to the fuel injector, to other parts of the engine, which are main factors contributing to engine noise.